Research to Inform Prescribed Fire Operations

Photo Credit

USDA Forest Service.

A firefighter holds a driptorch and hand radio monitors a prescribed burn in the Okanogan-Wenatchee National Forest.

Forest Service researchers are developing an innovative way to predict when to best use prescribed fire to clear forest of potential wildfire fuels for public safety as part of the agency’s 2022 10-year Wildfire Crisis Strategy.

The Wildfire Crisis Strategy requires increasing the use of controlled burns, or prescribed fire, to mitigate wildfire risks. In many regions, this will entail increasing prescribed burning by 5 to 10 times their current levels. Doing so will necessitate optimizing every aspect of these carefully planned fires, including identifying “burn windows” when weather, potential smoke dispersion, and vegetation conditions will meet rigorous safety standards.

Fire managers need to realistically assess the viability of burn windows with enough lead time to shift equipment and personnel from one area to another as needed.

Research meteorologists Sim Larkin and Brian Potter with the Pacific Northwest Research Station are working with partners at the Desert Research Institute and the University of Washington to meet this need. The team is developing a tool for forecasting weather conditions that affect the safety of prescribed fire and smoke dispersion weeks and even months ahead of potential burns.

The ability to assess whether seasonal weather patterns are moving into or out of prescribed burn areas as potential burn days approach will help managers evaluate the likelihood of viable burn dates.

Prescribed fire differs from wildfire in that it is an opportunity for forest managers to initiate fire in specific areas and use it as a tool to create desired conditions., Prescribed fire is affected by all the same weather properties that influence wildfire. It requires “Goldilocks” conditions that are not too hot and not too cold, and not too wet and not too dry so that managers can achieve their objectives and do so safely.

This study will identify weather needs based on expert land and fire manager guidance, climate forecast expertise, basic atmospheric science expertise, and data availability.

Objectives

• Assemble current seasonal forecasts, drought outlooks, and climate teleconnection data and adapt them for prescribed fire (e.g., by identifying their effects on smoke dispersion and other prescribed burn window parameters). 
• Develop tools that allow managers to view maps of the expected availability of burn windows based on customizable prescription parameters. 
• Develop tools that can track the evolution of seasonal forecasts and other data for specific project sites as the time frame of interest approaches.
• Assemble a group of managers to assess the data and guide development of the above tools. 
• Work with managers to create a methodology to develop an official national prescribed fire and smoke dispersion seasonal outlook map through two workshops.

Expected Products

• A spatial visualization tool that allows the user to specify a period of interest (e.g., March through mid-April) to identify weather, fuel-moisture, and smoke-dispersion conditions for forecasted burn windows. This mapping tool will allow the user to specify multiple locations and see how in sync these locations are with respect to specific days. 
• A tracking tool to view updates to seasonal forecasts, drought outlooks, and other information for specified time periods and locations. This information is crucial for identifying any changes to a potential burn window before executing a planned burn. 
• All original data, computer code, and protocols developed in this study will be made available as open source.

Expected Outcomes

• Data, tools, and processes to inform prescribed fire and fuels managers about the expected availability of prescribed fire windows on time scales of several weeks to several months. 
• The management application of the results will be direct and immediate. 
• The research aspects of the project will provide significant insight into methods and metrics for treatment of weather and climate forecast data as they relate to prescribed fire. Knowing the reliability and predictability of model predictions of the individual measures relevant to prescribed fire (e.g., temperature, precipitation, atmospheric humidity, wind speed and direction, mixing height) will allow future research to focus on improvements where they are most needed for management planning.

Metrics of Success

The project will culminate with a workshop. At this workshop the fuels and smoke managers will develop an overall assessment report on the state of the developed tools, the feasibility of issuing ongoing national outlooks, and recommendations for future work. This assessment will also constitute a direct measure of the success of this project.

Keywords: Controlled burn, prescribed fire, smoke dispersion, air quality, fire weather, smoke modeling.